Accelerator pedal module

ABSTRACT

An accelerator pedal module is provided that is actuated by the driver&#39;s foot for controlling the output of a drive engine. Frequently undesirable noise is generated by means of characteristic vibration in the restoring springs of prior pedal modules. The accelerator pedal module of this invention includes an intertwined multi-wire spring which helps to eliminate undesirable vibration of the restoring spring. The accelerator pedal module is provided for controlling the output of a drive engine of a vehicle and forces the pedal module from a full load stop, back to an idle stop

PRIOR ART

The invention is based on an accelerator pedal module for a motorvehicle.

There are already a number of disclosures (e.g. DE 34 11 455 A1; WO89/07706; WO 97/12780) in which a pivoting body is provided that can beactuated by the driver of the motor vehicle, wherein the position of thepivoting body is designated for establishing the power to be output bythe drive engine desired by the driver. A restoring spring is providedin order to restore the pivoting body to an idle position. In order toassure a reliable resetting of the pivoting body under allcircumstances, even if there should be a fracture of the restoringspring that restores the pivoting body into the idle position, tworestoring springs are usually provided. In order to assure that therestoring force is sufficient for restoring the pivoting body into theidle position when one of the two individual springs of the restoringspring breaks, the restoring spring must by and large be embodied assignificantly stronger than is needed for restoring the pivoting body.More precisely stated, in order to assure that the restoring force issufficient for restoring the pivoting body when one of the twoindividual springs of the restoring spring breaks, the overall restoringforce of the two restoring springs must be more than twice as great asis required. Many people who use the accelerator pedal module find thisunpleasant. Another disadvantage is the large amount of space requiredfor the two relatively large individual springs.

In order to give the driver as pleasant a feel as possible whenactuating the pivoting body, a friction element is provided, whichcounteracts an actuation of the pivoting body with a certain frictionalresistance. The expense for generating the frictional resistance,however, cannot be ignored and is difficult to produced due tofrequently very limited space conditions.

The restoring spring in the known embodiments has a slight tendency tovibrate. As a result, unpleasant noise is produced, which is caused bythe restoring spring. Sometimes the attempt is made to shift the noiseinto an inaudible range in terms of frequency by changing the length ofthe restoring spring. But this has other disadvantages, for example interms of strength. Sometimes a damping element is also insertedapproximately in the middle of the restoring spring in order to preventnoise. The damping element is provided, for example, between a housingand the restoring spring or between the two individual springs of therestoring spring. The insertion of this damping element, however,signifies an additional expense and also there is the danger of thedamping element getting clamped between the coils of the restoringspring and as a result, the restoring spring can have an unevenrestoring force. The damping element is comprised, for example, of afoam material resting against the coils of the restoring spring. Afurther disadvantage is that the durability and effectiveness of thisdamping element are limited. The installation of the damping elementbetween the spring coils requires a costly manual labor that isdifficult to automate.

ADVANTAGES OF THE INVENTION

The accelerator pedal module according to the invention has an advantageover the prior art that the functionally reliable operation of theaccelerator pedal module is significantly increased. Even with apotential damage to the restoring spring, the restoring force of therestoring spring only decreases slightly. Therefore it is advantageouslynot necessary to oversize the restoring spring far beyond the amountrequired for restoring the pivoting body. As a result, the restoringspring requires a particularly small amount of structural volume.

Through the internal friction of the multi-wire spring, i.e. through thefriction between the individual wires of the multi-wire spring, themulti-wire spring suppresses its own vibration. As a result, therestoring spring produces significantly less noise or no noise at alland the spring is prevented from fracturing due to its own vibrations.

Because the vibration damping takes place inside the restoring spring,the significant advantage is obtained that in the dimensioning of therestoring spring, no consideration or hardly any consideration has to betaken as to the natural frequency of the restoring spring.

Since fewer components are required with the accelerator pedal moduleembodied according to the invention, because two separate springspreviously required for safety reasons and an additional damping elementare not required in particular for the restoring spring, the expenditurefor the assembly is significantly reduced in an advantageous manner. Inparticular, no pre-assembled structural groups have to be formed.

The internal friction in the multi-wire spring is not only evident dueto the reduction in noise or the lack of noise, but without additionalexpense, this friction also advantageously produces a frictional forcethat counteracts the movement of the pivoting body, which gives a betterfeel when actuating the pivoting body. As a result, an additionalfrictional device can be advantageously eliminated or the additionalfrictional device can be sized smaller.

An additional damping element required for noise reduction is notnecessary, which as a result advantageously reduces the expensesignificantly when assembling the accelerator pedal module. Because inthe past, an additional damping element occasionally led tomalfunctions, a risk source for malfunctions is advantageouslyeliminated without expense.

Advantageous improvements and updates of the accelerator pedal moduledisclosed are possible by means of the measures set forth hereinafter.

If some or all of the individual wires of the multi-wire spring aresecured against drifting out of the multi-wire spring, then theadvantage is obtained that a sliding or drifting of an individual wireout of the multi-wire spring need not be feared even with an extendedalternating stress on the restoring spring.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferably selected, particularly advantageous exemplary embodiments ofthe invention are shown in simplified fashion in the drawings and willbe explained in more detail in the description that follows.

FIG. 1, illustrates a side view of a pedal module of this invention,

FIG. 2, illustrates a side view of a spring used in the pedal module,

FIG. 3, illustrates a cross sectional view of the spring,

FIG. 4, illustrates a cross section though the spring shown in FIG. 2also illustrating a retaining structure of one end of the spring, and

FIG. 5, illustrates a cross sectional view of a modification of thepedal module shown in FIG. 1.

DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

The accelerator pedal module embodied according to the invention can beused to control different drive engines. The drive engine is, forexample, a spark ignition engine, whose throttle valve is adjusted witha control motor. In this instance, the accelerator pedal module is used,for example, to produce electrical signals that are supplied to thecontrol motor that adjusts the throttle valve. The drive engine can,however, also be a diesel engine or an electric motor, wherein in theseinstances as well, electrical signals come from the accelerator pedalmodule, which, correspondingly converted, control the output of thedrive engine. The transmission of the driver's wishes from theaccelerator pedal module to the drive engine, however, can also occur ina purely mechanical fashion, for example by way of a cable control or aBowden control.

The accelerator pedal module is preferably disposed directly in theaction range of the driver of a motor vehicle. The pivoting body of theaccelerator pedal module is preferably the gas pedal directly actuatedby the driver's foot. If need be, however, it is also possible with notrouble to link a separate gas pedal or another mechanical operatinglever to the pivoting body of the accelerator pedal module using simplemechanical means.

FIG. 1 is a schematic depiction of an accelerator pedal module 1. Theaccelerator pedal module 1 includes a retaining structure 2, a pivotingbody 3, a friction device 4, a sensor 5, a restoring spring 8 and abearing point 9.

The retaining structure 2 is fastened to a chassis 12 symbolicallydepicted in FIG. 1 by means of a cross-hatching, preferably immediatelyin the foot region of a vehicle driver. The pivoting body 3 ispreferably actuated directly by the driver's foot; the pivoting body 3can in this instance also be called the gas pedal. However, it is alsopossible to couple a separate gas pedal to the pivoting body 3 by way ofa simple linkage.

The pivoting body 3 is supported at the bearing point 9 so that it canpivot in relation to the retaining structure 2. The sensor 5 senses theposition of the pivoting body 3 and sends a signal that corresponds tothe position of the pivoting body 3 to a control unit 14 via electricallines that are depicted with dashed lines in FIG. 1.

The sensor 5 is coupled on the one hand to the retaining structure 2 andon the other hand to the pivoting body 3 so that the movable part of thesensor 5 follows every movement of the pivoting body 3 in a play-freemanner.

As a function of the signals sent by the sensor 5 as well as othersignals sent to the control unit 14, the control unit 14 controls theoutput of the drive engine 16, which is symbolically depicted in FIG. 1.The drive engine 16 is, for example, a spark ignition engine, a dieselengine, a hybrid motor, an electric motor, or the like.

A full load stop 18 and an idle stop 20 are provided on the retainingstructure 2. If the pivoting body 3 is not actuated by the vehicledriver, then the pivoting body 3, driven by the restoring spring 8, isdisposed against the idle stop 20. This position is called the idleposition R below. The vehicle driver can actuate the pivoting body 3until the pivoting body 3 comes into contact with the full load stop 18.This position of the pivoting body 3 against the full load stop 18 iscalled the full load position V below. The full load position V of thepivoting body 3 is symbolically depicted in FIG. 1 by means of adot-and-dash line.

If the pivoting body 3 is disposed in the idle position R, then thedrive engine 16 operates, for example, with a minimal output providedthat the drive engine 16 is not operating with a higher output based onsignals of a transmitter 21. The pivoting body 3 can be adjusted over anactuation angle alpha (a). The actuation angle alpha (a) is 15°, forexample.

By pivoting the pivoting body 3 around the bearing point 9 over theactuation angle alpha (a), the driver can actuate the pivoting body 3from the idle position R into the full load position V. When thepivoting body 3 is not actuated, the restoring spring 8 assures that thepivoting body 3 moves into the idle position R. For safety reasons, theassurance must be made that even if the restoring spring 8 cannot actwith full force as a result of a defect, the remaining force of therestoring spring 8 is sufficient to restore the pivoting body 3 into theidle position R.

The restoring spring 8 is disposed inside a housing that is not shown inFIG. 1 for the sake of better visibility.

The restoring spring 8 is a multi-wire spring 8. The restoring spring 8,called the multi-wire spring 8 below, is embodied so that a sufficientlygreat restoring force for restoring the pivoting body 3 into its idleposition R is assured even when there is damage to the multi-wire spring8.

FIGS. 2 and 3 show the multi-wire spring 8 in detail form. FIG. 2 is aside view of the multi-wire spring 8 and FIG. 3 shows a cross sectionalarea of the multi-wire spring 8.

In all of the Figs. the same parts or parts which have the same functionare provided with the same reference numerals. Provided that nothing tothe contrary is mentioned or shown in the drawings, that which ismentioned and shown in relation to one of the Figs. also applies to theother exemplary embodiments. Provided that there is nothing to thecontrary in the explanations, the details of the different exemplaryembodiments can be combined with one another.

The multi-wire spring 8 is comprised of a number of intertwinedindividual wires. As shown in FIG. 3, the preferably selected multi-wirespring 8 is comprised of a first individual wire 8 a, a secondindividual wire 8 b, a third individual wire 8 c, a fourth individualwire 8 d, a fifth individual wire 8 e, a sixth individual wire 8 f, anda seventh individual wire 8 g. The seventh individual wire 8 g isdisposed centrally in the cross sectional area of the multi-wire spring8. The other individual wires 8 a to 8 f are wound tightly around theseventh individual wire 8 g. The individual wires 8 a to 8 f are woundhelically around the individual wire 8 g. The individual wires 8 a to 8g are intertwined with one another. The individual wires 8 a to 8 f arewound tightly around the central individual wire 8 g so that highfrictional forces can be transmitted between the individual wires 8 a to8 g. In other words, the individual wires 8 a to 8 g can only be slid inrelation to one another with an increased force. As a result of the moreor less tight winding of the individual wires 8 a to 8 g, the frictionalforces can be influenced in a desirable manner. In the side view, a lookis produced that is similar to that of an intertwined rope.

The multi-wire spring 8, which is suited for the exemplary embodimentshown in FIG. 1, is shown in detail form in FIG. 2, and is intertwinedout of the individual wires 8 a to 8 g, is wound on the whole like ahelical spring. When the two ends of the multi-wire spring 8 are actedon, the entire material cross section of the multi-wire spring 8 isloaded with torsion. This leads to relative movements between theindividual wires 8 a to 8 g. But since the individual wires 8 a to 8 gare wound or intertwined in relation to one another or around oneanother, and since lateral forces are transmitted between the individualwires 8 a to 8 g, frictional forces are produced between the individualwires 8 a to 8 g, which have a damping effect, which leads to a dampingof vibrations of the multi-wire spring 8. As a result, a characteristicvibration of the multi-wire spring 8 can be reliably prevented. Thisassures that noise caused by the multi-wire spring 8 is either notproduced at all or is only produced in a strongly damped manner.

The friction between the individual wires 8 a to 8 g of the multi-wirespring 8 also leads to the fact that upon actuation of the pivoting body3 (FIG. 1), a frictional force, which comes from the multi-wire spring 8and counteracts the movement of the pivoting body 3, acts on thepivoting body 3.

As a result, when the pivoting body 3 moves, a desired hysteresis isproduced. Therefore the friction device 4 (FIG. 1) can be eliminated orthe friction device 4 can be embodied as correspondingly weaker andtherefore simpler and smaller in structural volume.

FIG. 4 shows a cross section through the multi-wire spring 8, viewed inthe direction of the retaining structure 2. The intersecting plane isindicated in FIG. 1 with a dot-and-dash line and the viewing directionis indicated by means of an arrow labeled IV.

A circumferential groove 24 is provided on the end face of the retainingstructure 2. The spring end of the multi-wire spring 8 that engages theretaining structure 2 is inserted into the groove. A lateral groove 26is provided cross-wise to the circumferential groove 24. The lateralgroove 26 has a groove bottom. The groove bottom constitutes a stop face30 a. The end of the multi-wire spring 8 is angled so that the endprotrudes into the lateral groove 26. The multi-wire spring 8 ends inthe vicinity of the stop face 30 a or directly against the stop face 30a. The stop face 30 a constitutes a retention device 30. Instead ofbeing provided in a lateral groove, the stop face 30 a of the retentiondevice 30 can also be provided, for example, directly on the groovebottom of the circumferential groove 24. In this embodiment, which isnot depicted graphically, it is not necessary to angle the end of themulti-wire spring 8.

When there are load changes on the multi-wire spring 8, frictionalforces are transmitted between the individual wires 8 a to 8 g. This canlead to the fact that one or more of the individual wires 8 a to 8 g isvery slowly but continually slid in one direction. Therefore it canoccur that the one or the other of the individual wires 8 a to 8 g has atendency to drift out of the end face of the multi-wire spring 8. Theretention device 30 prevents one or more of the individual wires 8 a to8 g from drifting out of the end face of the multi-wire spring 8. Anindividual wire that drifts out can only come out so far until it restsagainst the stop face 30 a. In terms of the overall length of themulti-wire spring 8, a slight outward drift of an individual wire isinsignificant, which is why even coarse, easy-to-maintain measurementtolerances can be permitted in the retention device 30.

The proposal is made to embody the spring end of the multi-wire spring 8connected to the pivoting body 3 in the same manner as is explained inconnection with the spring end oriented toward the retaining structure2.

It is also possible to prevent the individual wires 8 a to 8 g fromdrifting out of the end face by virtue of the fact that on at least oneend of the multi-wire spring 8, at least some of the individual wires 8a to 8 g are reciprocally connected to one another. The individual wires8 a to 8 g can be connected to one another on one spring end, forexample by means of welding. But because the connecting of theindividual wires 8 a to 8 g on at least one spring end requires anadditional work cycle, reference is made to the proposed retentiondevice 30 (FIG. 4) as a favorable retention possibility.

Because particularly the center individual wire 8 g (FIG. 3) frequentlytends to drift out, the retention device 30 must be embodied so that itat least retains this individual wire 8 g. Depending on the type ofwinding of the multi-wire spring 8, the multi-wire spring 8 can possiblyalso be wound without the center individual wire 8 g.

FIG. 5 shows another selected, particularly advantageous exemplaryembodiment.

Viewed in the simplest terms, in the embodiment shown in FIG. 5, theretaining structure 2 is a hollow cylindrical formed body in which thepivoting body 3 is supported so that it can rotate. The pivoting body 3is essentially comprised of a shaft 3 a that is supported so that it canpivot and a lever 3 b that is connected to the shaft 3 a.

With the exception of the differences mentioned below, which essentiallyconcern the restoring spring 8, the accelerator pedal module 1 shown inFIG. 4 is embodied the same as is extensively described in the GermanPatent Disclosure DE 34 11 455 A1 and in the French Patent Disclosure FR25 62 010 A derived from it and in the derivative Italian Patent IT 1184 195 A so that essentially only the existing differences in relationto DE 34 11 455 A1 are discussed below in order to avoid an unnecessaryrepetition of that which is already known.

In contrast to the accelerator pedal module that is known from the abovementioned references, in the accelerator pedal module 1 (FIG. 5)embodied according to the invention, a multi-wire spring 8 is used thatis intertwined out of several, preferably at least three, andparticularly preferably seven individual wires 8 a to 8 g (FIG. 3). Asdescribed and demonstrated extensively in DE 34 11 455 A1, the restoringspring 8 is coupled to the retaining structure 2 on one end and iscoupled to the pivoting body 3 on the other. Although in contrast to theaccelerator pedal module known from DE 34 11 455 A1, in the acceleratorpedal module 1 embodied according to the invention, only the onemulti-wire spring 8 is used as the restoring spring 8, despite thisfact, a high degree of reliability is also produced even if some of theindividual wires 8 a to 8 g of the multi-wire spring 8 should fail.

Because the multi-wire spring 8 is comprised of a multitude ofindividual wires 8 a to 8 g, with a possible breakage of one of theindividual wires 8 a to 8 g, the restoring force only decreases by arelatively small amount. In comparison to the known accelerator pedalmodule, since only the one multi-wire spring 8 is required to achievethe necessary restoring reliability, the overall restoring force of therestoring spring 8 does not have to be as greatly oversized, which iswhy one can achieve the fact that the accelerator pedal module 1embodied according to the invention can be embodied as smaller than theaccelerator pedal module known from DE 34 11 455 A1.

In the exemplary embodiment according to FIG. 5, when the lever 3 b ofthe pivoting body 3 is actuated, the multi-wire spring 8 is acted onwith torsional forces. This leads to a bending stress on the materialcross section of the multi-wire spring 8. This produces relativemovements between the individual wires 8 a to 8 g of the multi-wirespring 8. This relative movement produces friction between theindividual wires 8 a to 8 g of the multi-wire spring 8. As a result ofthis friction, vibrations of the multi-wire spring 8 are prevented orare at least so intensely damped that no interfering characteristicvibrations are produced and therefore no unpleasant noise is generated.

Since the friction between the individual wires 8 a to 8 g of themulti-wire spring 8 counteracts a movement of the pivoting body 3 in thesame manner as the friction device 4, whose operation is describedextensively in DE 34 11 455 A1, the friction between the individualwires 8 a to 8 g can replace or at least support the friction device 4.

Therefore in comparison to the prior art known from DE 34 11 455 A1, thefriction device 4 can be embodied as weaker and consequently smaller involume and simpler, or the friction device 4 can be completelyeliminated.

So that the individual wires 8 a to 8 g cannot drift out of the end faceof the multi-wire spring 8, in the exemplary embodiment shown in FIG. 5as well, the respective retention device 30 is provided with the contactface 30 a at the place where the multi-wire spring 8 is coupled to theretaining structure 2 and at the place where the multi-wire spring 8 iscoupled to the pivoting body 3.

The foregoing relates to preferred exemplary embodiments of theinvention, it being understood that other variants and embodimentsthereof are possible within the spirit and scope of the invention, thelatter being defined by the appended claims.

What is claimed is:
 1. An accelerator pedal module for controlling anoutput delivered by a drive engine, with a pivoting body (3) that issupported at a bearing point (9) on a retaining structure (2), saidpivoting body 3 is pivoted around a pivot axis over a pivoting angle(a), a single restoring spring (8) that engages at least indirectly withthe retaining structure (2) and at least indirectly with the pivotingbody (3) is provided for restoring the pivoting body (3) into an idleposition (R), the single restoring spring (8) is a multi-wire spring (8)intertwined out of a number of individual wires (8 a-8 g), wherein, ifone of the wires of the multi-wire spring should break, the remainingwires of the multi-wire spring will still provide sufficient returnforce to the pivoting body, with very little loss of return force by themulti-wire spring.
 2. The accelerator pedal module according to claim 1,in which the multi-wire spring (8) is acted on with compressive forces.3. The accelerator pedal module according to claim 2, in which themulti-wire spring (8) is a compression spring, wherein the individualwires (8 a-8 g) are acted on with torsion.
 4. The accelerator pedalmodule according to claim 1, in which the multi-wire spring (8) is actedon with torsional forces.
 5. The accelerator pedal module according toclaim 4, in which the multi-wire spring (8) is a torsion spring, whereinthe individual wires (8 a-8 g) are stressed by bending.
 6. Theaccelerator pedal module according to claim 1, in which at least some ofthe individual wires (8 a-8 g) are secured against drifting out of themulti-wire spring (8) by means of a retention device (30).
 7. Theaccelerator pedal module according to claim 2, in which at least some ofthe individual wires (8 a-8 g) are secured against drifting out of themulti-wire spring (8) by means of a retention device (30).
 8. Theaccelerator pedal module according to claim 3, in which at least some ofthe individual wires (8 a-8 g) are secured against drifting out of themulti-wire spring (8) by means of a retention device (30).
 9. Theaccelerator pedal module according to claim 4, in which at least some ofthe individual wires (8 a-8 g) are secured against drifting out of themulti-wire spring (8) by means of a retention device (30).
 10. Theaccelerator pedal module according to claim 5, in which at least some ofthe individual wires (8 a-8 g) are secured against drifting out of themulti-wire spring (8) by means of a retention device (30).
 11. Theaccelerator pedal module according to claim 1, in which at least some ofthe individual wires (8 a-8 g) are connected on at least one end of themulti-wire spring (8) to prevent the individual wires from reciprocallysliding against one another.
 12. The accelerator pedal module accordingto claim 2, in which at least some of the individual wires (8 a-8 g) areconnected on at least one end of the multi-wire spring (8) to preventthe individual wires from reciprocally sliding against one another. 13.The accelerator pedal module according to claim 3, in which at leastsome of the individual wires (8 a-8 g) are connected on at least one endof the multi-wire spring (8) to prevent the individual wires fromreciprocally sliding against one another.
 14. The accelerator pedalmodule according to claim 4, in which at least some of the individualwires (8 a-8 g) are connected on at least one end of the multi-wirespring (8) to prevent the individual wires from reciprocally slidingagainst one another.
 15. The accelerator pedal module according to claim5, in which at least some of the individual wires (8 a-84 g) areconnected on at least one end of the multi-wire spring (8) to preventthe individual wires from reciprocally sliding against one another. 16.The accelerator pedal module according to claim 6, in which at leastsome of the individual wires (8 a-8 g) are connected on at least one endof the multi-wire spring (8) to prevent the individual wires fromreciprocally sliding against one another.